Pneumatic finger chuck



PNEUMATIC FINGER CHUCK Filed March 15, 1945 3 Sheets-Sheet INVENTOR. SA? 6mm/Ma Filed. March 15,. 1943 .3 Sheets-Shes?, 3

H INVENTR.

Patented Oct.`31, 1944 PNEUMATIC FINGER CHUCK Asa C. Goddard, Mentor, Ohio, assignor to Jack & Heintz, Inc., Bedford, Ohio, a corporation of Ohio Application March 15, 14943, Serial No. 479,217

6 Claims. (Cl. 279-106) This invention relates in general to chucks and has for one of its primary objects to provide a multiple finger chuck with a new and novel center shifting cam mechanism for imparting movement of the chuck ngers into and out of engagement with the work, wherein the construction and operation of they chuck will be simplified and improved in efficiency in clamping and releasing operations.

With the foregoing and other objects in View, the invention resides in the combination of parts and in the details of constructionhereinafter set forth in the following specification and appended claims, certain embodiments thereof being illustrated in the accompanying drawings, in which:

Figure 1 is a top plan view of the chuck, partly broken away and in cross section to show the construction of one of thechuckiingers, and showing the work not engaged by the fingers.

Figure 2 is a partial view in vertical section taken through the chuck showing the work in place and one nger in the first position, or released from the work.

Figure 3 is a View in similar sectionshowing L the finger in the second position, or raised against the work holder but not in clamping relationship therewith.

Figure 4 is a view in similar section showing the finger in'clamping relationship with the work.

Figure 5 is a View in section taken along line 5 5 of Figure 3.

Figure 6 is a schematic illustration of the relationship of the finger, cam and work as they obtain in Figure 2. i

Figure 7 is a similar illustration of the same parts as they appear in Figure 3. l

Figure 8 is a similar illustration of the same parts as they appear in Figure 4.

Referring more particularly to the drawings,

. the chuck may comprise three concentrically ar- ,ranged finger assemblies I 2 and 3 which are carried by and simultaneously operated by a Y plunger 4 into and out of engagement with the work 5.

Inasmu-ch as each finger assembly is identical in construction and carried by plunger 4 and simultaneously operated thereby, the three main operating positions of one finger assembly will be described in detail. Figure 2 shows the clamping finger E and its flange 'I in outward position andremoved and disengaged from the work 5. The finger is provided with a bolt 8 for removable engagement with a bar 9 which is pivotally connected by a bolt I0 to a cam I I. This cam is carried by plunger 4 and pivotally connected thereto by a pin I2 having a spherical extremity I3 contained between the flanges I4 and I5 of the plunger. The cam is also provided with an elliptical slot I6 to receive a bolt I'I carried by bar 9 which in turn is provided with an elliptical slot I8 through which boltl I1 passes and is held in place by a set screw I9. Thus bar 9 and cam II are movable and elements 29 and 2| for carrying the same are stationary but adjustable inwardly and outwardly in slots 22 and 23 and held in place by bolts 24 and 25. i

The movable bar 9, carrying the chuck finger, also carries a bolt 26 which extends through a circular opening 21 in the stationary member 20 and in this stationary member are arranged a pair of balancing compression coil springs 28 and 29 on either side of bolt 26 and held in place by set screws 30 and 3|. This balanced arrangement of springs 28 and 29 maintains the chuck finger in disengaged position as shown in Figures 2 and 6,

representing the first position in which bolt I'I is midway in slot I8 and at the right hand extremity of slot I6 as viewed in Figure-6.

A pulling of the plunger, pneumatically or otherwise from left to right, or from its rst position of Figure 2 to that of Figure 3 brings the finger 6 into abutment with the work holder 32 but the finger ange 'I not in clamping relationship with the work 5. During the movement of the assembly from the first position shown in Figures 2 and 6 to the second position shown in Figures 3 and '7, the nger carryingbar 9 and the cam II have rotated as a unit about bolt I1 as a stationary center. As finger 6 contacts work holder 32, as shown in Figures 3 and '7, the finger bar 9 is free to move vertically, bolt II still being in the same relationship in slots I6 and I8 as it was in the i'lrst position of Figure 6.

As this 'second position of Figure 6 occurs the fulcrum point for rotation of the cam plate I I shifts from bolt I'I to bolt I9. IA further pull on plunger 4 from left to right from its position of Figure 3 to that of Figure 4 also pulls the cam plate II and causes it to further rotate about its new fulcrum point I9. This causes the finger bar 9 to move vertically due to the restrictive guiding action of slot`I8 of bar 9 on the stationary center in the form of bolt I'I. This brings about a relative movement between bolt I1 and slot I6 and a consequent shift of position of bolt I1 laterally in slot I6 from right to left and Vertically upwardly in slot I8 to bring the nger ange 'I into clamping engagement with the work 5, as Viewed in Figures 5 and 8.

I claim:

l. In combination in a chuck, a work supporting table, a plurality of concentrically arranged work engaging chuck fingers, and means for moving said fingers simultaneously into and out of clamping engagement with said work, said means comprising a pivoted arm for carrying each finger and a plunger carrying a pivoted lever adjacent each arm, each of said arms and its corresponding lever being pivotally connected to each other and having slots substantially at right angles to each other and mounted for rotative and limited linear movement in diierent directions about a common stationary pivot, said lever and arm being adapted to rotate together about said common stationary pivot under urging of said plunger for a limited. degree determined by the slots of said arm and lever after which said levers fulcrum is shifted to its pivotal connection to said arm so as to guide said nger angul'arly into engagement with and subsequently linearly in another direction into clamping engagement with vsaid work'.

2. In combination in a chuck, a work supporting table, a plurality of concentrically arranged Work engaging chuck iingers, and means for moving'said ngers simultaneously into and out of clamping engagement with said work, said means, comprising a pivoted arm for carrying each ringer' and a plunger carrying a pivoted lever adjacent each arm, each of said arms and its corresponding lever being pivotally connected to each other and having slots substantially at right angles to each other and mounted for rotative and limited linear movement in different directions about a common stationary pi-vot, said lever and arm being mounted for dependent rotation together about said common stationary pivot under urging of said plunger and for dependent linear and rotative movement respectively about'the pivotal connection between said arm and lever.

3. In combination in a chuck, a work supporting table, a plurality of concentrically arranged Work engaging chuck fingers, and means for moving said fingers simultaneously into and out of clamping engagement with said Work, said means ycomprising a compound lever for carrying each finger and a plunger carrying one arm of said lever, the arms of said lever being mounted for rotative and limited linear movement about a common stationary pivot, said arms being adapted to rotate together about said common stati'onary pivot under urging of said plunger for a vlimited degree after which said levers fulc-rum 'is `shifted to the pivotal connection between said arms so as to guide said finge-r ang-ularly into engagement with and subsequently linearly in another direction into clamping engagement with said work.

4. In combination in a chuck, a work supporting table, a plurality of concentrically arranged work engaging chuck fingers, and means for moving said ngers simultaneously into and out of clamping engagement with said work, said means comprising a compound lever for carrying each linger and a plunger carrying one arm of said lever, the arms of said lever being mounted for rotative and limited linear movement in diierent directions about a common stationary pivot, said arms being adapted to rotate together about said common stationary pivot under urging of said plunger for a limited degree after which said levers iulcrum is shifted to the pivotal connection between said arms so as to guide said nger angularly into engagement with and subsequently linearly in another direction into clamping engagement with said Work.

5. In combination in a chuck, a Work supporting table, a plurality of concentrically arranged work engaging chuck fingers, and means for moving said ngers simultaneously into and out of clamping engagement with said work,said means including a compound lever comprising pivoted arm for carrying each finger and a pivoted lever adjacent each arm, a plunger for carrying said lever, each of said arms and its corresponding lever being pivotally connected to each other and having slots .substantially at right angles to each other and mounted for rotative and limited linear movement about a common stationary pivot, said lever and arm being adapted to rotate together about said common stationary pivot under urging cf said plunger for a limited degree determined by the slots of said arm and lever after which said levers fulcrum is shifted to its pivotal connection to said arm so as to guide said linger angularly into engagement with and Subsequently linearly in another direction into clamping engagement with said work.

6. In combination in a chuck, a Work supporting table, a plurality of concentrically arranged work engaging chuck fingers, and means for moving said iingers simultaneously into and out of clamping engagement with said Work, said means comprising a pivoted arm for carrying each finger and a plunger carrying a pivoted lever adjacent each arm, each of said arms and its corresponding lever being pivotally connected to each other and having slots substantially at right angles to each other and mounted for rotative and limited linear movement in about a Common stationary pivot, said lever and arm being adapted to rotate together about said common stationary pivot under urging of said plunger for a limited degree determined by the slots of said arm and lever after which said levers fulcrum is shifted to its pivotal connection to said arm so as to guide said ringer angularly into engagement with and subsequently linearly in another direction into clamping engagement with said work.

ASA C. GODDARD. 

